I have this same config as well, it's my only computer, and I use it primarily for software dev (Ruby on Rails work).
I first purchased this computer as an exercise in minimalism - came from a 2k8 MBP w/ 4 gigs ram. For the most part hasn't let me down, the exceptions doing some .NET dev in a Fusion Windows 7 VM which was a bit of a chore both speed and RAM constricted. Trying Eclipse dev was a bit slow as well, it's quite memory intensive. I wouldn't recommend it for large scale photo editing/encoding or the like, but for most people's use cases it's probably alright.
I will be upgrading to an Ivy Bridge 11" w/ 4 gigs when it's available. My biggest gripe might be battery life, I'm hoping they can squeeze out an extra 20% or so, or at least have it perform better under load.